Yep, that's almost the diagram you need; it doesn't show the GEN light. I think Dick/4TL8Ford has all the diagrams squirreled away on his website. I'll see if I can find it.

Note that the 3-wires can still still be internally regulated, so there may not be a separate regulator to hook up. And there may not be an advantage to a GM alternator, you can use a Ford setup and it will almost be plug'n'play...

 

Oh man.....I hate electrical. But I'm not giving up!

Havi, most of the diagrams in that thread were custom from Dan that he drew up for me. I found what I needed in emails so they're all irrelevant anyways.

It's a shame what happened...........again.


Ross, wait wait wait, you're saying the the 3-wires are not typically internally regulated like the 1-wires are, so I'll still have to have a regulator? Does that mean I will not only have to have a reg, but actually replace the one I have now?

Nuts.

EDIT: I haven't looked at my bookmarks in a while, but apparently I had saved these two threads. They are helping me a lot actually!
https://www.ford-trucks.com/forums/9...tra-wires.html
https://www.ford-trucks.com/forums/9...or-wiring.html

 

Here is some good reading on the subject;
GM Alternator In A Ford
http://www.madelectrical.com/electri...hreewire.shtml

Bobby

 

^OK, read both of those.

Wow, looks like I have a serious issue--If I want to run a 3-wire alternator, I'm going to need to rewire my truck.

So I guess the alt conversion is thrown out the window.

 

No, I don't think you need to rewire your truck. Worst case scenario is you might have to add a new circuit or "beef up" and existing one, all the original wiring can basically stay in place.

The 3 wire alternator basically needs 2 connections to operate. The big post on the rear goes directly to the battery or to the battery side of the starter solenoid. The 2 wire terminal is easy enough; one side goes to the big battery post, the other to the idiot light circuit.

An idiot light for an alternator is also the exciter signal for the alternator. When you turn the key on (alternator not turning) power flows from the ignition switch through the idiot light and out to the alternator wich grounds the circuit and turns the light on. When the engine is running and alternator is turning and working an opposing voltage flows back down the idiot light circuit towards the light. Since the light now has 12 volts coming at it from oposite directions there can be no current flow and the light does not light. If the alternator quits charging current will flow and the light will come on.

Bobby

 

Here's what I don't get though. In the article, it mentions that you SHOULD NOT use the battery side/terminal to power all of the accessories on the vehicle(which is what I've seen done all the time since it's easy...), but that they should be powered off of "the main power distribution junction"...........

...Now, where is the "main power distribution junction" located on our trucks? Do we even have one?

I know where the stater solenoid is, and I know it's wrong to just run more and more wires to the battery or solenoid in order to power things.

But where is the main power junction on these trucks?

 

Here are the diagrams Dan posted, with everything NOT involved in the conversion deleted. If you go to the boneyard and grab a Ford alternator with external regulator, you grab the regulator and the harness that connects the alternator and regulator, as well as the one that feeds alterantor power to the system (big wire with fusible link). If you use a GM one wire, there is only one wire -- the rest of the job is DELETING or disconnecting wires as Big Job described above.

Maybe Bobby or BigJob can say how the idiot light fits into the Ford system, I'm not clear on that?

Honestly, if you aren't 100% on what is needed, take it to a shop that does electrical, and have them do it! The last thing you need is to smoke off a $100 alternator, or set the whole system on fire!

 

***EDIT***:To support my wanting of a 3-wire, I just found a newer 3-wire alt in my own back yard. It was mounted to a chevy 327 in a ****** that was totaled in Feb '10. Thing worked fine to the best of out knowledge.

I am doing the GM 3-wire if I do it. I have been talked out of the 1-wire. I am also going internally regulated, I'm not switching to an alt so I can still deal with an external reg. The article is pretty helpful understanding the shortfalls of the 1-wire.


I still don't understand where or what the "main power distribution junction" is.


What exactly does this entail? What would I be doing?

 

Just got my truck about rewired. 289 12 volt system IASF transitor reg. started it up and only had 12 volts at batt., less with load. Hooked "I"wire from reg. to ignition on key switch and it charges 14.6. is this okay?

 

You can use the starter solenoid as the "power distribution block"

OK, lets see if we can walk you through this. I think that the "A" terminal on your original voltage regulator is the circuit to the idiot light in the dash, this might be a yellow wire. This wire will need to be connected to terminal #1 of the 2 wire connector on the GM alternator. Terminal #2 of the 2 wire connector will connect to the BAT terminal on the rear of the alternator. You will also have to run a lenght of wire, 10 or 12 gauge (preferable with a small length of fusible link) over to the battery side of the starter solenoid.

I beleive that will do it. I'll try and pull up a 1956 wiring schematic this afternoon and verify

Bobby

 

OK, I have re-read some things and thought a little more and am now comfortable with finally doing the conversion; I just need some 10 gauge wiring and a few other things.


However I'm still somewhat worried about how the voltage/wattage plays a role in my old outdated electrical system. I have no clue how many amps/wats/volts that thing is...

goddammit, I don't even know what watts/volts amps are and why I need to know about all 3!!!

 

Relax, you'll be fine.
I didn't get a chance to look over the schematics last night. I'll take a look some time today

Bobby

 

Since your truck is already 12v, the wiring is sized correctly for the loads connected. Loads don't draw more power just because there is more current available. If you add new high-draw loads, (A/C, power windows, etc) then you'd need to upgrade. You do need to upgrade the power feed out of the alternator because it can put out more when charging the battery.

And like I said, if you aren't completely comfortable doing this, get someone to help you (in person) who is, or take it to a shop!!

 

PS -- IMO the "problems" with 1-wire alt's (mostly spread by one website) are way overblown. I've been running a 1-wire for 5 yrs and have had zero problems. A 3-wire has some advantages but mostly on complex electrical systems with EFI and a bunch of big-draw accessories.

 

I agree, I've never had any issues with single wire alternators. There's milliions of them out there on tractors, boats, heavy equipment, etc working day in and day out without any problems whatsoever.

Bobby